Interesting.
Not one person here has mentioned Tinfoil For Facebook.
Since I'm a geeky tech type and have rooted every single one of my phones at some point I've never used the default facebook app nor messenger. I suppose I should go check and see if FB has any of my call or sms data - but I gather that the person that wrote tinfoil objected massively to the things he/she saw and prevented it. FWIW - tinfoil allows one to flip back to basic web mode and hit messages that way - although it does get bafffed with the 'install messenger now' page when you try to hit messages from the current default display mode.